Identify the location where the sex cells of each reproductive system mature.

The correct answer is D -ovary for the left (female reproductive system) and Q-epididymis for right (male reproductive system).

Ovaries are the primary female sex organs that produce the female gamete (ovum) and several steroid hormones (ovarian hormones). The ovaries are located one on each side of the lower abdomen. Each ovary is about 2 to 4 cm in length and is connected to the pelvic wall and uterus by ligaments. The formation of a mature female gamete is called oogenesis. Oogenesis takes place in ovary and is initiated during the embryonic development stage when a couple of million gamete mother cells (oogonia) are formed within each fetal ovary.

Testis are the primary sex organ in males.  Spermatogenesis is process by which sperm is produced in testis. Spermatogenesis starts at the age of puberty due significant increase in the secretion of gonadotropin releasing hormone (GnRH). This, if you recall, is a hypothalamic hormone. Sperms released from the seminiferous tubules, are transported by the accessory ducts. Secretions of epididymis, vas deferens, seminal vesicle and prostate are essential for  maturation and motility of sperms. The seminal plasma along with the sperm constitutes the semen.

the answer is:

carbon dioxide

the areas around the equator